EP 1426773 A1 20040609 - CAPACITANCE MEASURING CIRCUIT, CAPACITANCE MEASURING INSTRUMENT, AND MICROPHONE DEVICE
Title (en)
CAPACITANCE MEASURING CIRCUIT, CAPACITANCE MEASURING INSTRUMENT, AND MICROPHONE DEVICE
Title (de)
KAPAZITÄTSMESS-SCHALTUNG, KAPAZITÄTSMESSINSTRUMENT UND MIKROFONEINRICHTUNG
Title (fr)
CIRCUIT DE MESURE DE LA CAPACITE, INSTRUMENT DE MESURE DE LA CAPACITE ET DISPOSITIF DE MICROPHONE
Publication
Application
Priority
- JP 0209138 W 20020906
- JP 2001269993 A 20010906
Abstract (en)
An electrostatic capacitance detection circuit 10 comprises an AC voltage generator 11, an operational amplifier 14 of which non-inverting input terminal is connected to specific potential (a ground in this example), an impedance converter 16, a resistance (R1) 12 connected between the AC voltage generator 11 and an inverting input terminal of the operational amplifier 14, a resistance (R2) 13 connected between the inverting input terminal of the operational amplifier 14 and an output terminal of the impedance converter 16, and an impedance element (a capacitor) 15 connected between an output terminal of the operational amplifier 14 and an input terminal of the impedance converter 16, and a capacitor to be detected 17 is connected between the input terminal of the impedance converter 16 and specific potential. The electrostatic capacitance detection circuit 10 and the capacitor 17 are located adjacently. <IMAGE>
IPC 1-7
IPC 8 full level
G01N 27/06 (2006.01); G01N 27/22 (2006.01); G01R 27/26 (2006.01); H04R 29/00 (2006.01)
CPC (source: EP KR US)
G01R 27/26 (2013.01 - EP KR US); H04R 29/004 (2013.01 - EP US)
Designated contracting state (EPC)
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR IE IT LI LU MC NL PT SE SK TR
DOCDB simple family (publication)
EP 1426773 A1 20040609; EP 1426773 A4 20050921; CN 1271418 C 20060823; CN 1551990 A 20041201; KR 100715062 B1 20070504; KR 20040041603 A 20040517; NO 20032012 D0 20030505; NO 20032012 L 20030703; TW I221195 B 20040921; US 2005017737 A1 20050127; US 7019540 B2 20060328; WO 03023421 A1 20030320
DOCDB simple family (application)
EP 02767922 A 20020906; CN 02817401 A 20020906; JP 0209138 W 20020906; KR 20047003329 A 20020906; NO 20032012 A 20030505; TW 91120333 A 20020905; US 48876304 A 20040929